What is Core Web Vitals?

Core Web Vitals are three metrics Google uses to measure real user experience on your website. They directly influence your search ranking — pages with poor Core Web Vitals get demoted, especially on mobile.

LCP (Largest Contentful Paint) measures loading performance: how long until the biggest visible element (hero image, heading, video) fully renders. Good: under 2.5 seconds. Excellent: under 1.5 seconds.

CLS (Cumulative Layout Shift) measures visual stability: how much the page layout shifts unexpectedly while loading. A CLS of 0 means nothing moved. Good: under 0.1. Common causes: images without dimensions, ads injected after load, fonts swapping.

INP (Interaction to Next Paint) measures responsiveness: how long between a user action (click, tap, key press) and the browser updating the screen. Good: under 200ms. Poor INP usually means too much JavaScript on the main thread.

You can check your Core Web Vitals in Google Search Console (under Experience), Google PageSpeed Insights, or Chrome DevTools (Lighthouse). Search Console shows real user data from Chrome browsers; Lighthouse shows lab data from a simulated environment.

The ranking impact is real but proportional — Core Web Vitals won't override great content and strong backlinks, but they break ties between otherwise equal pages.